1. Field of the Invention
This invention relates to simulated samples of airborne substances found at facility sites and more specifically to a device and method for introducing airborne solid or liquid contaminants or both into a controlled environment for the production of simulated samples that can be used in analytical method development and validation studies.
2. Background
Air samples containing dust and other substances from institutional and manufacturing facilities are currently used by industrial hygienists for monitoring air quality control. Air samples are collected at the facility site onto filters using high volume air sampling devices. These air samples are devoted to air quality monitoring programs and an abundant number of such air samples are not available for the development and validation of new analytical testing and monitoring methodologies.
In addition, manufacturing and other "on-site" samples may not contain the required substances or contain them in such minute or uncontrolled quantities as to be unsuitable for test and methodology development. Although it is possible to introduce the substance into the air at the on-site facility for the purpose of collecting a specific type of sample, this can involve closing the facility while sample introduction and preparation takes place or risking exposure of on-site facility workers to the particular substance under study. Neither of these alternatives are very satisfactory. In fact, in some cases neither alternative may be a viable option when the substance is a particularly toxic or otherwise dangerous material. In addition, it is often difficult to control and/or identify other co-substances that may also be present at a facility site when samples are taken. In a similar vein, it may be desirable to study the effects of one or more of these co-substances on the validity of an analytical method for a specific substance. Such combinations often are not available "on-demand" at a facility site.
A facility site typically does not afford a good source of the large number of samples with the variation in substance and co-substance concentrations required for new analytical method development and validation studies. A need exists for a device and method for simulating actual facility samples in large quantities with a wide range of substance and co-substance concentrations that does not require closing a facility site or risking worker exposure to the various substances required for testing and development of existing and new contaminant detection and evaluation methodologies.